1. Field of the Invention
This invention relates to a device for sorting hosiery, and more particular to a pneumatic conveying system that interfaces with a multi-station sock sewing machine.
2. Description of the Prior Art
Conventionally, hosiery are knit in the form of elongated circular tubes with the toe end open. According to prior art, the stockings are delivered, in containers, to a seaming station. The operator of the seaming station then picks up the stockings and passes them through a sewing machine to trim and close the open toe, while the stockings are turned inside-out. Stockings are then delivered to an inspection station where they are visually inspected. After inspection, individual stockings are everted pneumatically through a hollow inspection form and delivered to a collection point. As delivered, they are in the rightside-out condition.
Some time ago, it was recognized that the repeated manual operations recited above increased the cost of hosiery by slowing down production and increasing the number of "seconds" due to imperfections caused by the inspection process, such as pulled threads. Thus, devices were developed in which a combination turning and inspection form is moveable from the inspection station to a sewing station to permit the toe of the stocking to be seamed while it remains on the form. However, the use of these devices were not entirely satisfactory because hosiery had to be inspected before the seaming operation, leading to some undetected defects. In some devices, the operator had to turn and inspect the hosiery on the form and wait for the form to deliver the hose to the seaming station and return before the next stocking can be placed on the form.
U.S. Pat. No. 3,486,471 (De Spain) describes an improved method and device wherein the hosiery is turned on a form at a first work station by a first operator, and then advanced on the form to a second work station where a second operator closes the toe while it remains on the form. The hosiery is then returned to the first work station, where the seamed hosiery is inspected by the first operator and subsequently everted through a hosiery receiving passage in the form. A duct system, connected to a source of pneumatic pressure differential, was provided to establish a flow of air through a hosiery receiving passage when they are at the first work station.
U.S. Pat. No. 3,420,196 (Edwards et at.) deserves a method and means for processing tubular fabric articles in which ends of the articles are dosed in an integrated operation that is capable of high-speed production that requires relatively little handling, reducing labor requirements and the danger of damage of the articles during handling. Tubular fabric articles are placed on forms at a receiving station, where an end of the article is closed while it remains on its form. The form advances through an end closing station, and articles are removed from the forms at a removal station. Articles may be inspected while they are on the forms at the receiving station, and everted as they are removed from the forms after end closing. This device comprises conveyor means that convey article carrying forms through the receiving end closing and removal stations, with the forms arranged for receiving open-ended articles at the receiving station such that open ends of the articles are disposed at the outer ends of the forms for closing of the article ends by closure means in the end closing station while the articles remain on the forms as the form advance through the end closing station to the removal station at which removal means remove the closed end articles from the forms.
The forms are hosiery inspecting and turning forms disposed to extend laterally from a conveyor means for ready access for mounting the hosiery articles thereon and to present the articles ends conveniently for horizontal feeding to the closure means, which is a sewing machine disposed adjacent the outer ends of the forms for feeding the toe ends of the articles through as the forms advance continuously through the end closing station. Inspection is accomplished on the inspecting and turning forms, where the toes are guided into the sewing machine. Then the toes are closed and the articles are everted and removed from the forms at the removal station. Two operators are required, one at the receiving station and another at the toe closing station.
However, prior art devices suffer from a number of disadvantages. For example, styles cannot be mixed; they must be fed into the system one style at a time. Because two or more styles are often produced at the same time in hosiery plants, it would be advantageous to be able to feed more than one style into the system at once, and to sort the different styles from each other and from seconds. Another disadvantage of the prior art devices is that seconds must be removed before the seaming operation, as there is no way to sort seconds or styles after they enter this operation. Moreover, the prior art devices for collecting and sorting socks are not fast enough for the ten-tube turrets used at today's speeds. It would thus be advantageous to provide a sock sorter that permitted a plurality of styles, as well as seconds, to enter the seaming operation while being sorted later. Furthermore, it would be advantageous to provide a system that has a plurality of separating and sorting functions. Thus, a hosiery factory could run at least two styles of hosiery at one time, while allowing seconds to be finished, sorted, and counted in the same run, at maximum efficiency, and with maximum return on salvaged seconds.
Today, machines such as "Detexomat" machines are used in the sock industry for the sole purpose of closing the toe of a sock. An operator loads a sock onto a tube. The operator also has the opportunity to remove the sock in the event the sock is not of first quality. However, when the operator removes the sock from the cycle, the machine must continue through its cycle empty. The sewing machine still runs, even though there are no socks to be sewn. While this is going on, the operator misses three socks because of the break in rhythm and removing the seconds sock from the tube. While each sock factory has its own system of handling seconds, generally the socks are collected, counted, and boxed. Meanwhile, a report must be made, and the socks must be tracked in the warehouse. (A box of sock seconds presently has a value of about $200.00 to $250.00.)
At some point, the accumulation of these seconds becomes a great problem. The problem is so great that an operator or operators must be taken off producing first quality production to seam the accumulated seconds. The operator replaces the sock on the tube, even though it was previously removed from the tube only a fraction of a second from the time it would have been seamed had it not been removed as a second.
Thus, although a satisfactory first quality sock line is produced by this method, the cost to produce the second quality line (in energy and manpower) is greater than the cost to produce the first quality line.
There is thus a need for an add-on device for a toe closer that can track a sock through the toe closer, and then, in accordance with a signal provided by the operator prior to the sewing step, direct the flow of the sock to an appropriate destination, in accordance with the determined quality of the sock and the style.